Re: f2fs compile problem in next-20191220 on x86-32

[Chao Yu]

On 2019/12/25 21:04, Pavel Machek wrote:
> On Sun 2019-12-22 16:49:17, Pavel Machek wrote:
>> Hi!
>>
>> I'm getting this:
>>
>>   LD      .tmp_vmlinux1
>>   ld: fs/f2fs/file.o: in function `f2fs_truncate_blocks':
>>   file.c:(.text+0x2968): undefined reference to `__udivdi3'
>>   make: *** [Makefile:1079: vmlinux] Error 1
>>
>> when attempting to compile kernel for x86-32.
> 
> David bisected it:
> 
> https://bugzilla.kernel.org/show_bug.cgi?id=205967
> 
> And the bug is actually easy to see:
> 
> +int f2fs_truncate_blocks(struct inode *inode, u64 from, bool lock)
> +{
> +       u64 free_from = from;
> +
> +       /*
> +        * for compressed file, only support cluster size
> +        * aligned truncation.
> +        */
> +       if (f2fs_compressed_file(inode)) {
> +               size_t cluster_size = PAGE_SIZE <<
> +                                       F2FS_I(inode)->i_log_cluster_size;
> +
> +               free_from = roundup(from, cluster_size);
> 
> #define roundup(x, y) (                                 \
> {                                                       \
>         typeof(y) __y = y;                              \
>         (((x) + (__y - 1)) / __y) * __y;                \
> }                                                       \
> 
> div64 is needed instead of div in the roundup macro. Or actually... It
> is quite stupid to use roundup like this on value that is power of
> two, right?

This has been fixed in dev branch, could you check that? People still saw this
issue because linux-next did not update after we fix this bug.

https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git/commit/?h=dev

Thanks,

> 
> Best regards,
> 									Pavel
>